1 files changed, 562 insertions, 0 deletions

diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c
new file mode 100644
index 00000000000..b18140ff2b9
--- /dev/null
+++ b/sound/firewire/amdtp.c
@@ -0,0 +1,562 @@
+/*
+ * Audio and Music Data Transmission Protocol (IEC 61883-6) streams
+ * with Common Isochronous Packet (IEC 61883-1) headers
+ *
+ * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/firewire.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <sound/pcm.h>
+#include "amdtp.h"
+
+#define TICKS_PER_CYCLE		3072
+#define CYCLES_PER_SECOND	8000
+#define TICKS_PER_SECOND	(TICKS_PER_CYCLE * CYCLES_PER_SECOND)
+
+#define TRANSFER_DELAY_TICKS	0x2e00 /* 479.17 µs */
+
+#define TAG_CIP			1
+
+#define CIP_EOH			(1u << 31)
+#define CIP_FMT_AM		(0x10 << 24)
+#define AMDTP_FDF_AM824		(0 << 19)
+#define AMDTP_FDF_SFC_SHIFT	16
+
+/* TODO: make these configurable */
+#define INTERRUPT_INTERVAL	16
+#define QUEUE_LENGTH		48
+
+/**
+ * amdtp_out_stream_init - initialize an AMDTP output stream structure
+ * @s: the AMDTP output stream to initialize
+ * @unit: the target of the stream
+ * @flags: the packet transmission method to use
+ */
+int amdtp_out_stream_init(struct amdtp_out_stream *s, struct fw_unit *unit,
+			  enum cip_out_flags flags)
+{
+	if (flags != CIP_NONBLOCKING)
+		return -EINVAL;
+
+	s->unit = fw_unit_get(unit);
+	s->flags = flags;
+	s->context = ERR_PTR(-1);
+	mutex_init(&s->mutex);
+	s->packet_index = 0;
+
+	return 0;
+}
+EXPORT_SYMBOL(amdtp_out_stream_init);
+
+/**
+ * amdtp_out_stream_destroy - free stream resources
+ * @s: the AMDTP output stream to destroy
+ */
+void amdtp_out_stream_destroy(struct amdtp_out_stream *s)
+{
+	WARN_ON(!IS_ERR(s->context));
+	mutex_destroy(&s->mutex);
+	fw_unit_put(s->unit);
+}
+EXPORT_SYMBOL(amdtp_out_stream_destroy);
+
+/**
+ * amdtp_out_stream_set_rate - set the sample rate
+ * @s: the AMDTP output stream to configure
+ * @rate: the sample rate
+ *
+ * The sample rate must be set before the stream is started, and must not be
+ * changed while the stream is running.
+ */
+void amdtp_out_stream_set_rate(struct amdtp_out_stream *s, unsigned int rate)
+{
+	static const struct {
+		unsigned int rate;
+		unsigned int syt_interval;
+	} rate_info[] = {
+		[CIP_SFC_32000]  = {  32000,  8, },
+		[CIP_SFC_44100]  = {  44100,  8, },
+		[CIP_SFC_48000]  = {  48000,  8, },
+		[CIP_SFC_88200]  = {  88200, 16, },
+		[CIP_SFC_96000]  = {  96000, 16, },
+		[CIP_SFC_176400] = { 176400, 32, },
+		[CIP_SFC_192000] = { 192000, 32, },
+	};
+	unsigned int sfc;
+
+	if (WARN_ON(!IS_ERR(s->context)))
+		return;
+
+	for (sfc = 0; sfc < ARRAY_SIZE(rate_info); ++sfc)
+		if (rate_info[sfc].rate == rate) {
+			s->sfc = sfc;
+			s->syt_interval = rate_info[sfc].syt_interval;
+			return;
+		}
+	WARN_ON(1);
+}
+EXPORT_SYMBOL(amdtp_out_stream_set_rate);
+
+/**
+ * amdtp_out_stream_get_max_payload - get the stream's packet size
+ * @s: the AMDTP output stream
+ *
+ * This function must not be called before the stream has been configured
+ * with amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and
+ * amdtp_out_stream_set_midi().
+ */
+unsigned int amdtp_out_stream_get_max_payload(struct amdtp_out_stream *s)
+{
+	static const unsigned int max_data_blocks[] = {
+		[CIP_SFC_32000]  =  4,
+		[CIP_SFC_44100]  =  6,
+		[CIP_SFC_48000]  =  6,
+		[CIP_SFC_88200]  = 12,
+		[CIP_SFC_96000]  = 12,
+		[CIP_SFC_176400] = 23,
+		[CIP_SFC_192000] = 24,
+	};
+
+	s->data_block_quadlets = s->pcm_channels;
+	s->data_block_quadlets += DIV_ROUND_UP(s->midi_ports, 8);
+
+	return 8 + max_data_blocks[s->sfc] * 4 * s->data_block_quadlets;
+}
+EXPORT_SYMBOL(amdtp_out_stream_get_max_payload);
+
+static void amdtp_write_s16(struct amdtp_out_stream *s,
+			    struct snd_pcm_substream *pcm,
+			    __be32 *buffer, unsigned int frames);
+static void amdtp_write_s32(struct amdtp_out_stream *s,
+			    struct snd_pcm_substream *pcm,
+			    __be32 *buffer, unsigned int frames);
+
+/**
+ * amdtp_out_stream_set_pcm_format - set the PCM format
+ * @s: the AMDTP output stream to configure
+ * @format: the format of the ALSA PCM device
+ *
+ * The sample format must be set before the stream is started, and must not be
+ * changed while the stream is running.
+ */
+void amdtp_out_stream_set_pcm_format(struct amdtp_out_stream *s,
+				     snd_pcm_format_t format)
+{
+	if (WARN_ON(!IS_ERR(s->context)))
+		return;
+
+	switch (format) {
+	default:
+		WARN_ON(1);
+		/* fall through */
+	case SNDRV_PCM_FORMAT_S16:
+		s->transfer_samples = amdtp_write_s16;
+		break;
+	case SNDRV_PCM_FORMAT_S32:
+		s->transfer_samples = amdtp_write_s32;
+		break;
+	}
+}
+EXPORT_SYMBOL(amdtp_out_stream_set_pcm_format);
+
+static unsigned int calculate_data_blocks(struct amdtp_out_stream *s)
+{
+	unsigned int phase, data_blocks;
+
+	if (!cip_sfc_is_base_44100(s->sfc)) {
+		/* Sample_rate / 8000 is an integer, and precomputed. */
+		data_blocks = s->data_block_state;
+	} else {
+		phase = s->data_block_state;
+
+		/*
+		 * This calculates the number of data blocks per packet so that
+		 * 1) the overall rate is correct and exactly synchronized to
+		 *    the bus clock, and
+		 * 2) packets with a rounded-up number of blocks occur as early
+		 *    as possible in the sequence (to prevent underruns of the
+		 *    device's buffer).
+		 */
+		if (s->sfc == CIP_SFC_44100)
+			/* 6 6 5 6 5 6 5 ... */
+			data_blocks = 5 + ((phase & 1) ^
+					   (phase == 0 || phase >= 40));
+		else
+			/* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
+			data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
+		if (++phase >= (80 >> (s->sfc >> 1)))
+			phase = 0;
+		s->data_block_state = phase;
+	}
+
+	return data_blocks;
+}
+
+static unsigned int calculate_syt(struct amdtp_out_stream *s,
+				  unsigned int cycle)
+{
+	unsigned int syt_offset, phase, index, syt;
+
+	if (s->last_syt_offset < TICKS_PER_CYCLE) {
+		if (!cip_sfc_is_base_44100(s->sfc))
+			syt_offset = s->last_syt_offset + s->syt_offset_state;
+		else {
+		/*
+		 * The time, in ticks, of the n'th SYT_INTERVAL sample is:
+		 *   n * SYT_INTERVAL * 24576000 / sample_rate
+		 * Modulo TICKS_PER_CYCLE, the difference between successive
+		 * elements is about 1386.23.  Rounding the results of this
+		 * formula to the SYT precision results in a sequence of
+		 * differences that begins with:
+		 *   1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
+		 * This code generates _exactly_ the same sequence.
+		 */
+			phase = s->syt_offset_state;
+			index = phase % 13;
+			syt_offset = s->last_syt_offset;
+			syt_offset += 1386 + ((index && !(index & 3)) ||
+					      phase == 146);
+			if (++phase >= 147)
+				phase = 0;
+			s->syt_offset_state = phase;
+		}
+	} else
+		syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
+	s->last_syt_offset = syt_offset;
+
+	if (syt_offset < TICKS_PER_CYCLE) {
+		syt_offset += TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
+		syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
+		syt += syt_offset % TICKS_PER_CYCLE;
+
+		return syt & 0xffff;
+	} else {
+		return 0xffff; /* no info */
+	}
+}
+
+static void amdtp_write_s32(struct amdtp_out_stream *s,
+			    struct snd_pcm_substream *pcm,
+			    __be32 *buffer, unsigned int frames)
+{
+	struct snd_pcm_runtime *runtime = pcm->runtime;
+	unsigned int channels, remaining_frames, frame_step, i, c;
+	const u32 *src;
+
+	channels = s->pcm_channels;
+	src = (void *)runtime->dma_area +
+			s->pcm_buffer_pointer * (runtime->frame_bits / 8);
+	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+	frame_step = s->data_block_quadlets - channels;
+
+	for (i = 0; i < frames; ++i) {
+		for (c = 0; c < channels; ++c) {
+			*buffer = cpu_to_be32((*src >> 8) | 0x40000000);
+			src++;
+			buffer++;
+		}
+		buffer += frame_step;
+		if (--remaining_frames == 0)
+			src = (void *)runtime->dma_area;
+	}
+}
+
+static void amdtp_write_s16(struct amdtp_out_stream *s,
+			    struct snd_pcm_substream *pcm,
+			    __be32 *buffer, unsigned int frames)
+{
+	struct snd_pcm_runtime *runtime = pcm->runtime;
+	unsigned int channels, remaining_frames, frame_step, i, c;
+	const u16 *src;
+
+	channels = s->pcm_channels;
+	src = (void *)runtime->dma_area +
+			s->pcm_buffer_pointer * (runtime->frame_bits / 8);
+	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+	frame_step = s->data_block_quadlets - channels;
+
+	for (i = 0; i < frames; ++i) {
+		for (c = 0; c < channels; ++c) {
+			*buffer = cpu_to_be32((*src << 8) | 0x40000000);
+			src++;
+			buffer++;
+		}
+		buffer += frame_step;
+		if (--remaining_frames == 0)
+			src = (void *)runtime->dma_area;
+	}
+}
+
+static void amdtp_fill_pcm_silence(struct amdtp_out_stream *s,
+				   __be32 *buffer, unsigned int frames)
+{
+	unsigned int i, c;
+
+	for (i = 0; i < frames; ++i) {
+		for (c = 0; c < s->pcm_channels; ++c)
+			buffer[c] = cpu_to_be32(0x40000000);
+		buffer += s->data_block_quadlets;
+	}
+}
+
+static void amdtp_fill_midi(struct amdtp_out_stream *s,
+			    __be32 *buffer, unsigned int frames)
+{
+	unsigned int i;
+
+	for (i = 0; i < frames; ++i)
+		buffer[s->pcm_channels + i * s->data_block_quadlets] =
+						cpu_to_be32(0x80000000);
+}
+
+static void queue_out_packet(struct amdtp_out_stream *s, unsigned int cycle)
+{
+	__be32 *buffer;
+	unsigned int index, data_blocks, syt, ptr;
+	struct snd_pcm_substream *pcm;
+	struct fw_iso_packet packet;
+	int err;
+
+	if (s->packet_index < 0)
+		return;
+	index = s->packet_index;
+
+	data_blocks = calculate_data_blocks(s);
+	syt = calculate_syt(s, cycle);
+
+	buffer = s->buffer.packets[index].buffer;
+	buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
+				(s->data_block_quadlets << 16) |
+				s->data_block_counter);
+	buffer[1] = cpu_to_be32(CIP_EOH | CIP_FMT_AM | AMDTP_FDF_AM824 |
+				(s->sfc << AMDTP_FDF_SFC_SHIFT) | syt);
+	buffer += 2;
+
+	pcm = ACCESS_ONCE(s->pcm);
+	if (pcm)
+		s->transfer_samples(s, pcm, buffer, data_blocks);
+	else
+		amdtp_fill_pcm_silence(s, buffer, data_blocks);
+	if (s->midi_ports)
+		amdtp_fill_midi(s, buffer, data_blocks);
+
+	s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
+
+	packet.payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
+	packet.interrupt = IS_ALIGNED(index + 1, INTERRUPT_INTERVAL);
+	packet.skip = 0;
+	packet.tag = TAG_CIP;
+	packet.sy = 0;
+	packet.header_length = 0;
+
+	err = fw_iso_context_queue(s->context, &packet, &s->buffer.iso_buffer,
+				   s->buffer.packets[index].offset);
+	if (err < 0) {
+		dev_err(&s->unit->device, "queueing error: %d\n", err);
+		s->packet_index = -1;
+		amdtp_out_stream_pcm_abort(s);
+		return;
+	}
+
+	if (++index >= QUEUE_LENGTH)
+		index = 0;
+	s->packet_index = index;
+
+	if (pcm) {
+		ptr = s->pcm_buffer_pointer + data_blocks;
+		if (ptr >= pcm->runtime->buffer_size)
+			ptr -= pcm->runtime->buffer_size;
+		ACCESS_ONCE(s->pcm_buffer_pointer) = ptr;
+
+		s->pcm_period_pointer += data_blocks;
+		if (s->pcm_period_pointer >= pcm->runtime->period_size) {
+			s->pcm_period_pointer -= pcm->runtime->period_size;
+			snd_pcm_period_elapsed(pcm);
+		}
+	}
+}
+
+static void out_packet_callback(struct fw_iso_context *context, u32 cycle,
+				size_t header_length, void *header, void *data)
+{
+	struct amdtp_out_stream *s = data;
+	unsigned int i, packets = header_length / 4;
+
+	/*
+	 * Compute the cycle of the last queued packet.
+	 * (We need only the four lowest bits for the SYT, so we can ignore
+	 * that bits 0-11 must wrap around at 3072.)
+	 */
+	cycle += QUEUE_LENGTH - packets;
+
+	for (i = 0; i < packets; ++i)
+		queue_out_packet(s, ++cycle);
+}
+
+static int queue_initial_skip_packets(struct amdtp_out_stream *s)
+{
+	struct fw_iso_packet skip_packet = {
+		.skip = 1,
+	};
+	unsigned int i;
+	int err;
+
+	for (i = 0; i < QUEUE_LENGTH; ++i) {
+		skip_packet.interrupt = IS_ALIGNED(s->packet_index + 1,
+						   INTERRUPT_INTERVAL);
+		err = fw_iso_context_queue(s->context, &skip_packet, NULL, 0);
+		if (err < 0)
+			return err;
+		if (++s->packet_index >= QUEUE_LENGTH)
+			s->packet_index = 0;
+	}
+
+	return 0;
+}
+
+/**
+ * amdtp_out_stream_start - start sending packets
+ * @s: the AMDTP output stream to start
+ * @channel: the isochronous channel on the bus
+ * @speed: firewire speed code
+ *
+ * The stream cannot be started until it has been configured with
+ * amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and
+ * amdtp_out_stream_set_midi(); and it must be started before any
+ * PCM or MIDI device can be started.
+ */
+int amdtp_out_stream_start(struct amdtp_out_stream *s, int channel, int speed)
+{
+	static const struct {
+		unsigned int data_block;
+		unsigned int syt_offset;
+	} initial_state[] = {
+		[CIP_SFC_32000]  = {  4, 3072 },
+		[CIP_SFC_48000]  = {  6, 1024 },
+		[CIP_SFC_96000]  = { 12, 1024 },
+		[CIP_SFC_192000] = { 24, 1024 },
+		[CIP_SFC_44100]  = {  0,   67 },
+		[CIP_SFC_88200]  = {  0,   67 },
+		[CIP_SFC_176400] = {  0,   67 },
+	};
+	int err;
+
+	mutex_lock(&s->mutex);
+
+	if (WARN_ON(!IS_ERR(s->context) ||
+		    (!s->pcm_channels && !s->midi_ports))) {
+		err = -EBADFD;
+		goto err_unlock;
+	}
+
+	s->data_block_state = initial_state[s->sfc].data_block;
+	s->syt_offset_state = initial_state[s->sfc].syt_offset;
+	s->last_syt_offset = TICKS_PER_CYCLE;
+
+	err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
+				      amdtp_out_stream_get_max_payload(s),
+				      DMA_TO_DEVICE);
+	if (err < 0)
+		goto err_unlock;
+
+	s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
+					   FW_ISO_CONTEXT_TRANSMIT,
+					   channel, speed, 0,
+					   out_packet_callback, s);
+	if (IS_ERR(s->context)) {
+		err = PTR_ERR(s->context);
+		if (err == -EBUSY)
+			dev_err(&s->unit->device,
+				"no free output stream on this controller\n");
+		goto err_buffer;
+	}
+
+	amdtp_out_stream_update(s);
+
+	s->packet_index = 0;
+	s->data_block_counter = 0;
+	err = queue_initial_skip_packets(s);
+	if (err < 0)
+		goto err_context;
+
+	err = fw_iso_context_start(s->context, -1, 0, 0);
+	if (err < 0)
+		goto err_context;
+
+	mutex_unlock(&s->mutex);
+
+	return 0;
+
+err_context:
+	fw_iso_context_destroy(s->context);
+	s->context = ERR_PTR(-1);
+err_buffer:
+	iso_packets_buffer_destroy(&s->buffer, s->unit);
+err_unlock:
+	mutex_unlock(&s->mutex);
+
+	return err;
+}
+EXPORT_SYMBOL(amdtp_out_stream_start);
+
+/**
+ * amdtp_out_stream_update - update the stream after a bus reset
+ * @s: the AMDTP output stream
+ */
+void amdtp_out_stream_update(struct amdtp_out_stream *s)
+{
+	ACCESS_ONCE(s->source_node_id_field) =
+		(fw_parent_device(s->unit)->card->node_id & 0x3f) << 24;
+}
+EXPORT_SYMBOL(amdtp_out_stream_update);
+
+/**
+ * amdtp_out_stream_stop - stop sending packets
+ * @s: the AMDTP output stream to stop
+ *
+ * All PCM and MIDI devices of the stream must be stopped before the stream
+ * itself can be stopped.
+ */
+void amdtp_out_stream_stop(struct amdtp_out_stream *s)
+{
+	mutex_lock(&s->mutex);
+
+	if (IS_ERR(s->context)) {
+		mutex_unlock(&s->mutex);
+		return;
+	}
+
+	fw_iso_context_stop(s->context);
+	fw_iso_context_destroy(s->context);
+	s->context = ERR_PTR(-1);
+	iso_packets_buffer_destroy(&s->buffer, s->unit);
+
+	mutex_unlock(&s->mutex);
+}
+EXPORT_SYMBOL(amdtp_out_stream_stop);
+
+/**
+ * amdtp_out_stream_pcm_abort - abort the running PCM device
+ * @s: the AMDTP stream about to be stopped
+ *
+ * If the isochronous stream needs to be stopped asynchronously, call this
+ * function first to stop the PCM device.
+ */
+void amdtp_out_stream_pcm_abort(struct amdtp_out_stream *s)
+{
+	struct snd_pcm_substream *pcm;
+
+	pcm = ACCESS_ONCE(s->pcm);
+	if (pcm) {
+		snd_pcm_stream_lock_irq(pcm);
+		if (snd_pcm_running(pcm))
+			snd_pcm_stop(pcm, SNDRV_PCM_STATE_XRUN);
+		snd_pcm_stream_unlock_irq(pcm);
+	}
+}
+EXPORT_SYMBOL(amdtp_out_stream_pcm_abort);